diff --git a/evm/vm/base.py b/evm/vm/base.py
index 377af865d2..567c2ef25d 100644
--- a/evm/vm/base.py
+++ b/evm/vm/base.py
@@ -163,8 +163,7 @@ def import_block(self, block):
 
     def mine_block(self, *args, **kwargs):
         """
-        Mine the current block. Proxies to the current block's mine method.
-        See example with FrontierBlock. :meth:`~evm.vm.forks.frontier.blocks.FrontierBlock.mine`
+        Mine the current block. Proxies to self.pack_block method.
         """
         block = self.block
         self.pack_block(block, *args, **kwargs)
@@ -460,18 +459,18 @@ def get_state_class(cls):
 
         return cls._state_class
 
-    def get_state(self, chaindb=None, block_header=None, prev_headers=None):
+    def get_state(self, chaindb=None, block_header=None):
         """Return state object
         """
         if chaindb is None:
             chaindb = self.chaindb
-        if block_header is None:  # TODO: remove
+        if block_header is None:
             block_header = self.block.header
-        if prev_headers is None:
-            prev_headers = self.get_prev_headers(
-                last_block_hash=self.block.header.parent_hash,
-                db=self.chaindb,
-            )
+
+        prev_headers = self.get_prev_headers(
+            last_block_hash=self.block.header.parent_hash,
+            db=self.chaindb,
+        )
         receipts = self.block.get_receipts(self.chaindb)
         return self.get_state_class()(
             chaindb,
diff --git a/evm/vm/forks/byzantium/constants.py b/evm/vm/forks/byzantium/constants.py
index 4b4688dc82..579a78a232 100644
--- a/evm/vm/forks/byzantium/constants.py
+++ b/evm/vm/forks/byzantium/constants.py
@@ -7,3 +7,6 @@
 
 
 EIP649_BLOCK_REWARD = 3 * denoms.ether
+
+EIP658_TRANSACTION_STATUS_CODE_FAILURE = b'\x00'
+EIP658_TRANSACTION_STATUS_CODE_SUCCESS = b'\x01'
diff --git a/evm/vm/forks/byzantium/vm_state.py b/evm/vm/forks/byzantium/vm_state.py
index ec728ca451..17b4041bb9 100644
--- a/evm/vm/forks/byzantium/vm_state.py
+++ b/evm/vm/forks/byzantium/vm_state.py
@@ -5,6 +5,10 @@
 from evm.vm.forks.spurious_dragon.vm_state import SpuriousDragonVMState
 
 from .computation import ByzantiumComputation
+from .constants import (
+    EIP658_TRANSACTION_STATUS_CODE_FAILURE,
+    EIP658_TRANSACTION_STATUS_CODE_SUCCESS,
+)
 
 
 class ByzantiumVMState(SpuriousDragonVMState):
@@ -13,8 +17,13 @@ class ByzantiumVMState(SpuriousDragonVMState):
     def make_receipt(self, transaction, computation):
         old_receipt = _make_frontier_receipt(self, transaction, computation)
 
+        if computation.is_error:
+            state_root = EIP658_TRANSACTION_STATUS_CODE_FAILURE
+        else:
+            state_root = EIP658_TRANSACTION_STATUS_CODE_SUCCESS
+
         receipt = Receipt(
-            state_root=b'' if computation.is_error else b'\x01',
+            state_root=state_root,
             gas_used=old_receipt.gas_used,
             logs=old_receipt.logs,
         )
diff --git a/evm/vm/forks/frontier/vm_state.py b/evm/vm/forks/frontier/vm_state.py
index c160dd199f..612323877f 100644
--- a/evm/vm/forks/frontier/vm_state.py
+++ b/evm/vm/forks/frontier/vm_state.py
@@ -248,8 +248,6 @@ def validate_block(self, block):
                     )
                 )
 
-        # XXX: Should these and some other checks be moved into
-        # VM.validate_block(), as they apply to all block flavours?
         if len(block.uncles) > MAX_UNCLES:
             raise ValidationError(
                 "Blocks may have a maximum of {0} uncles.  Found "
diff --git a/evm/vm_state.py b/evm/vm_state.py
index 5a2cebf96c..edd60a74cd 100644
--- a/evm/vm_state.py
+++ b/evm/vm_state.py
@@ -77,16 +77,6 @@ def difficulty(self):
     def gas_limit(self):
         return self.block_header.gas_limit
 
-    #
-    # chaindb
-    #
-    # @property
-    # def chaindb(self):
-    #     return self._chaindb
-
-    def set_chaindb(self, db):
-        self._chaindb = db
-
     #
     # state_db
     #
@@ -132,8 +122,8 @@ def revert(self, snapshot):
         with self.state_db() as state_db:
             # first revert the database state root.
             state_db.root_hash = state_root
-            # now roll the underlying database back
 
+        # now roll the underlying database back
         self._chaindb.revert(checkpoint_id)
 
     def commit(self, snapshot):
@@ -205,11 +195,9 @@ def apply_transaction(
         """
         Apply transaction to the given block
 
-        :param vm_state: the VMState object
         :param transaction: the transaction need to be applied
         :param block: the block which the transaction applies on
-        :param is_stateless: if is_stateless, call VMState.add_transactionto set block
-        :type vm_state: VMState
+        :param is_stateless: if is_stateless, call self.add_transaction to set block
         :type transaction: Transaction
         :type block: Block
         :type is_stateless: bool
@@ -234,16 +222,15 @@ def apply_transaction(
 
     def add_transaction(self, transaction, computation, block):
         """
-        Add a transaction to the given block and save the block data into chaindb.
+        Add a transaction to the given block and
+        return `trie_data` to store the transaction data in chaindb in VM layer.
 
         Update the bloom_filter, transaction trie and receipt trie roots, bloom_filter,
         bloom, and used_gas of the block.
 
-        :param vm_state: the VMState object
         :param transaction: the executed transaction
         :param computation: the Computation object with executed result
         :param block: the Block which the transaction is added in
-        :type vm_state: VMState
         :type transaction: Transaction
         :type computation: Computation
         :type block: Block